.main {
    padding: 20px 0;
    min-height: calc(100% - 140px);
}
.main_container {
    position: relative;
    width: 1100px;
    margin: 0 auto 0 auto;
}
.article_left_content {
    width: 720px;
    float: left;
}
.left_markdown {
    background: #fff;
    box-shadow: 0 8px 16px 0 rgba(7,17,27,.05);
    border-radius: 12px;
    box-sizing: border-box;
    padding: 30px 40px 30px 40px;
    position: relative;
    margin-bottom: 80px;
}
.article_right_menu {
    width: 344px;
    float: right;
    background: #fff;
    box-shadow: 0 8px 16px 0 rgba(7,17,27,.05);
    border-radius: 10px;
    box-sizing: border-box;
    position: fixed;
    right: 22%;
}
.markNav-title {
    height: 40px;
    line-height: 40px;
    margin-left: 23px;
    font-size: 18px;
    font-weight: 600;
}